Solar power generation system and method
A power generation system includes integrated photovoltaic (PV) panels. Each of the integrated PV panel includes photovoltaic cells, a junction coupler coupling the photovoltaic cells in series, in parallel, or in combinations thereof, output terminals, and a DC to AC converter coupled between the junction coupler and the output terminals. The DC to AC converter includes switching devices and the integrated PV panels are coupled in series at the respective output terminals. A controller is provided in the power generation system for generation switching command signals for the switching devices of the integrated PV panels to synthesize an output voltage of the power generation system.
1. A power generation system comprising:
integrated photovoltaic (PV) panels, each integrated PV panel comprising photovoltaic cells, a junction coupler coupling the photovoltaic cells in series, in parallel, or in combinations thereof, output terminals, and a DC to AC converter comprising switching devices coupled between the junction coupler and the output terminals,
wherein integrated PV panels are coupled in series at the respective output terminals and wherein an output voltage of each integrated PV panel includes a stepped voltage waveform comprising a positive DC voltage level and a negative DC voltage level; and
a controller for generating switching command signals for the switching devices to synthesize an output voltage of the power generation system.
2. The power generation system of claim 1 , wherein strings of series coupled integrated PV panels are connected in parallel.
3. The power generation system of claim 1 comprising a junction box to hold the junction coupler and the DC to AC converter.
4. The power generation system of claim 1 , wherein the switching devices comprise silicon carbide devices.
5. The power generation system of claim 1 , wherein the DC to AC converter comprises a H-Bridge DC to AC converter or a half bridge DC to AC converter.
6. The power generation system of claim 5 , wherein an output voltage of the H-Bridge DC to AC converter comprises a three level stepped voltage waveform including positive DC voltage, negative DC voltage, and zero voltage levels.
7. The power generation system of claim 6 , wherein durations for each of the voltage levels for each of the H-Bridge DC to AC converters are varied over a period of time.
8. The power generation system of claim 5 , wherein an output voltage of the power generation system is given by m=2s+1, wherein m is a number of levels in output voltage of the H-Bridge DC to AC converter and s is a number of integrated PV panels in the power generation system.
9. The power generation system of claim 1 , wherein the controller comprises a maximum power point tracking controller.
10. The power generation system of claim 1 wherein the power generation system comprises a three phase power generation system.
11. The power generation system of claim 10 , wherein the power generation system comprises three strings of the series connected integrated PV panels.
12. The power generation system of claim 11 , wherein output terminals of the three strings are connected in a star arrangement or a delta arrangement.
13. The power generation system of claim 1 comprising transformer-less connection to a power grid.
14. A photovoltaic (PV) energy power system installation method, comprising:
connecting integrated PV panels in series, each integrated PV panel including photovoltaic cells, a junction coupler coupling the photovoltaic cells in series, in parallel, or in combinations thereof, output terminals, and a DC to AC converter comprising switching devices coupled between the junction coupler and the output terminals; and
coupling the connected integrated PV panels to a grid or a load;
wherein an output voltage of each integrated PV panel includes a stepped voltage waveform comprising a positive DC voltage level and a negative DC voltage level.
15. The power generation system of claim 1 , wherein the stepped voltage waveform comprises a pulse width modulated voltage waveform.